Minimum close carton clamp



June 4, 1963 D. A. HARRIS 3,092,274

MINIMUM CLOSE CARTON CLAMP Filed Sept. 26, 1960 s Sheets-Sheet 1 H 2 INVENTOR. Donald A. Harris Buckhorn, Cheaiham 8r Blore ATTORNEYS June 4, 1963 D. A. HARRIS MINIMUM CLOSE CARTON CLAMP 3 Sheets-Sheet 2 Filed Sept. 26, 1960 INVENTOR.

Donald A. Harris .Buckhorn, Chen-Thom 8 Blore AT TORNEYS June 4, 1963 D, HARRls 3,092,274

MINIMUM CLOSE CARTON CLAMP Filed Sept. 26, 1960 3 Sheets-Sheet 3 i r l 1 E J.1: ---r-,-i 1 I Fig. '8

INVENTOR.

ATTORNEYS Buckhorn, Chearham 8 Blore United States Patent Ofi ice 3,092,274 Patented June 4, 1963 3,092,274 MINE {UM CLOSE CARTON CLAMP Donald A. Harris, Vancouver, Wash, assignor to Hyster Company, Portland, Greg, a corporation of Nevada Filed Sept. 26, 1960, Ser. No. 58,373 1 Qlaim. Ci. 2 14--620) This invention relates to industrial lift trucks and particularly to a clamp attachment for such a truck.

The patent to Ehmann, Re. 23,694, shows a clamp attachment of the general type under consideration, in which the clamp arms are movable from inner positions, within the lateral boundaries of the clamp arm frame, to outer positions beyond such boundaries. This enables the picking up of a wide range of loads of different widths. The loads usually are packages, cartons, boxes and the like. For convenience, the term carton will be used hereinafter to refer to such loads.

It is not unusual to dimension cartons which are to be loaded in confined spaces, such as boxcars, so that a predetermined number of cartons will properly fit in sideby-side relation between the side walls of the car. In loading the cartons, one carton is deposited as near as the clamp arms will allow to one side wall, and another carton as near as possible to the other side wall. Assuming that three cartons are designed to fit between the walls, it is obvious that the two deposited cartons will have to be moved away from one another and against the side walls to make room for the third carton and also the clamp arms engaging the carton. At present, this operation must be carried out by hand because the truck is not capable of performing this operation.

A main object of the present invention is to provide a truck having clamp arms capable of clamping and carrying a load in the usual fashion, but which are also designed to perform the carton separating operation dis cussed above.

. A more specific object is to provide a truck having clamp arms of the type just mentioned which may be moved inwardly to positions against or next to one another to facilitate their insertion between two cartons, and which may be moved outwardly to separate cartons, and which may be moved to positions beyond the lateral boundaries of the frame on which they are mounted to facilitate the handling of a load wider than such frame.

A further object is to provide a truck having clamp arms as described above in which all fixed parts associated with the clamp arms are within the lateral boundaries of the clamp frame, and all movable parts have contracted positions within such boundaries.

A further object is to provide for an industrial lift truck clamp arm attachment of the character described above, and particularly one which is compact.

A still further object is to provide a truck and attachment as above described in which there is a clamp arm frame mounted for side shifting movement relative to the truck body.

Various other objects of the present invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a top view of the front part of a truck having an attachment of the present invention;

FIG. 2 is a front view of the attachment;

FIG. 3 is a side elevation of the attachment;

FIG. 4 is a vertical section taken along line 4-4 of FIG. 2.;

FIG. 5 is a vertical section taken along line 5-5 of FIG. 3;

FIG. 6 is a vertical section taken along line 6-6 of FIG. 5;

FIG. 7 is a diagrammatic view of a hydraulic circuit for a clamp arm; and

FIG. 8 is a schematic view illustrating the operation of the attachment.

Referring to FIG. 1, the truck has a body 11 at the front end of which is a vertical extensible mast of conventional form having outer mast sections 13 receiving movable inner mast sections 14. The outer mast sections 13 are pivotally connected at their lower portions by supports 15 to the front axle or to the body of the truck.

The mast is tilted forwardly or rearwardly in conven tional fashion such as under the influence of tilt cylinders (not shown) having piston rods 17 equipped with clevises 19 pivotally connected to ears 21 on the rear of the outer mast sections 13.

There is a load carriage frame which includes spaced upright side members 25 fixed at their front edges to an upper cross member 27 (FIGS. 1 and 3) and a lower cross member 29 (FIG. 3). The side members 25 have rollers 31 received by the inner mast sections to guide the carriage frame for vertical movement.

The mast is extended and the carriage elevated in conventional fashion such as by a hydraulic ram 33 (FIG. 1) mounted on a support 35 fixed to the lower portions of outer mast sections 13.

Clamp Arm Frame There is a clamp arm frame mounted on the carriage frame for side shifting movement. The clamp arm frame includes spaced upright side plates 41 and 43 held in fixed spaced relation by a number of cross elements including four guide tubes (FIG. 2) 45, 47, 49 and 51. There is also a guide bar 53- (FIG. 1) connecting the side plates and passing through spaced sleeves 55 and 57. The sleeves are fixed to a tie plate 59 (FIGS. 4 and 5) which bears against the front of the cross member 27 (FIG. 4). Each sleeve also has secured thereto a downwardly and rearwardly extending support lug 61 (FIG. 4) fitting behind a rib 63 provided on the upper edge of the cross member 27.

The sleeve assembly, which includes the sleeves 55 and 57, the tie plate 59, and the lugs 61, is prevented from sidewise movement relative to the carriage frame by a stoplug 71 (FIGS. 5 and 6) which is fixed to the tie member 59 and fits within one slot 73 of a number of slots formed in the rib 63.

A review of the above shows that the sleeves 55 and 57 are in adjustable fixed relation with respect to the carriage frame and support the clamp arm frame by means of the bar 51. Also the clamp arm frame can be shifted sideways by the bar 51 sliding through the sleeves 55 and 57.

At its lower portion the clamp arm frame has a pair of laterally spaced mounting strips 81 (FIGS. 4 and 5) secured to the rear surfaces of the guide tubes 49 and 51. These strips carry vertical rollers 83 which engage the front face of the lower cross member 29. A pair of hooklike retaining pieces 84 (FIG. 4) are bolted to blocks 85 in turn secured to the mounted pieces 81. The retaining pieces book under a depending rib 86 formed on the lower edge of the cross member 29.

The retaining pieces may be removed to enable the clamp arm frame to be raised to selectively position the stop lug 71 in the slots 73.

The clamp arm frame may be shifted laterally by a double acting piston and cylinder unit 87 (FIGS. 1 and 5) having a rod 88 connected to an angle lug 89 (FIG. 5) secured to the rear of the guide tubes 45 and 47. The unit has the cylinder thereof connected to a lug 90 '(FIG. 5) secured to the sleeve 57 (which is stationary).

Fluid under pressure is supplied to and relieved from the unit 87 under the control of a three position reversing valve (not shown) mounted on the body, preferably adjacent the valve 135. In one position, the valve causes the clamp arm frame to shift one way and in another :position to shift the opposite way, and in the third position to remain in a desired position.

' Clamp Arms 1 There are a pair of clamp arms 91 and '93 (FIGS. 1 and 2) each having a base member 94 provided with a pair of mounting pieces '95 (FIGS. 1 and 4) secured to the outer ends of .a pair of cylindrical slides 97. The slides for arm 91 fit in guide tubes 47 and 51, and the slides for arm 93 fit in guide tubes 45 and 49. The tubes and side plates are provided with slots 99 to accommodate the mounting pieces 95 when the arms are moved inwardly of the side plates 41 and 43. It is apparent that the slots extend inwardly an extent so that the inner ends of oppositely directed slots overlap to permit the arms 91 and 93 to be moved to positions against one another or very close to one another. This relationship will be considered as a contiguous relationship. It is also apparentthat the arms 91 and 93 may be moved outwardly to positions substantially beyond the laatgral boundaries of the clamp frame and of the truck o y.

, Each arm includes a pair of load engaging pads 1100 (FIG. 1) mounted on the ends of a pair of vertically spaced equalizer members which are secured at Operation The operation is best described in connection with FIGS. 7 and 8. When it is desired to move the arms 91 and 93 from the solid line outer positions in FIG. 8, thevalve 135 is shifted to its FIG. 7 position to supply fluid to the cylinders of the arms. Referring to FIG. 7, fluid supplied by the conduit 137 to the cylinder 121 may pass through passage 139 and conduit 141 to be eifective their central portions to the associated base member 94.

It is apparent that the arms can engage a load between the arms by means of the pads 100, and can engage loads outside "of the arms by virtue of the fiat outer faces of the base members 94.

Piston and Cylinder'Units I ber 9410f the arm 91. The inner end of the cylinder 101 is connected to a crosshead in the form of a plate 113 (FIGS. 2 and 4). The crosshead is formed with a curved recess 115 (FIG. 4) the walls of which slidably engage. the exterior surface of the guide ,49. The crosshead 113 is also formed with a second curved recess to embrace asleeve 117. (FIG. 2) to 'whichit is secured.

The sleeve slidably fits on a guide rod 119 connected at its ends to the side plates 41 and 43. Thus the inner end of the cylinder 101 is mounted for guided sliding movement relative to theclamp arm frame.

There is a second cylinder 121 (FIGS. 2,7 and 8) forthe arm 91. This cylinder has a threaded connection 123 (FIG. 3) at its outer end with the side plate 41. There is a piston 125 (FIGS. ,7 and 8) for the cylinder having a rod 127 connected to the crosshead 113.

FIG. 7 shows the hydraulic circuitry for the cylinders 101 and 121. A pump 131 on the truck body supplies fluid under pressure through a pressure conduit 133- to 'a manually operable three position reversing valve 135 on the truck'body. A conduit 137 leads to the outer or left-hand .end of the cylinder 121. The piston 125 and the rod 127. are formed with a passage 139 communi- 'catingwith a short conduit 141 (compare FIGS. 7 and 2). The conduit connects to the outer or left-hand end of the cylinder 101. A second short conduit 143 (compare FIGS. 7 and 2) connects the right-hand end of the cylinder 101 to a passage 145 formed in the rod 127. A conduit 149 connects the right-hand end of the cylinder 121with the valve 135. A return line 151 connects the valve 135 to the sump 153.

a The arm 93 has similar piston and cylinder units similarly mounted and'connected. Similar reference numer- "als are employed in designating the parts for both arms,

against the rod end of the piston 103. However, the effective area of the piston 125 is greater than that of the piston 103. Hence piston 125 first moves to the right carrying the crosshead 113, cylinder 101 piston 103, rod and arm 91 inwardly. After the piston completes its travel, piston 103 is forced to the right to 'move the arm 91 still farther to the right to the broken line position shown in FIG. 8.

While pistons 125 and 103 are moving to the right, the fluid in the left-hand ends of the cylinders 101 and 121 is discharged through conduit 149, the discharge fluid in the cylinder101 traveling through the conduit 143 and passage 145 to the conduit 149.

While arm '91 is being so moved inwardly, arm 93 has been similarly moved inwardly by its piston and cylinder units to the broken line'position shown in FIG. 8. Now, the arms can be inserted between a pair of cartons and the arms moved outwardly to shove the cartons outwardly, by shifting the valve to its reversing position.

7 To pick up a load, the arms-91 and 93 are separated a distance exceeding the width of. a load, then moved inwardly to clamp the load. In depositing the load, if the load is not in the desired alignment with the place at which it is to be deposited, the side shift piston and cylinder unit 87 can be operated to shift the clamp arm frame and thus the arms and their load into such alignment.

It is pointed out that all, of the parts which function i has been set forth, this is only illustrative and the attainment of such a relationship of the arms has many other uses.

Having described the invention in what is considered to be the preferred embodiment thereof, it is desired that 'it be understood that the invention is not to be limited other than by the provisions of the following claim.

I claim:

An attachment for a lift truck comprising a frame for mounting on the truck to be elevated by a hoist on the truck;

said frame having a width not exceeding that of said truck;

a pair of load engaging members;

said frame including a pair of vertically spaced horizontally disposed guide tubes for each load engaging member;

each load engaging member having connections with a pair of slides slidably received by its guide tubes to provide for movement of said load engaging members from inner positions to outer positions;

each pair of guide tubes being slotted inwardly from the set of ends thereof closest the outer position of its load engaging member to pass the connections for its load engaging members during inward movement of the latter;

the slots of one pair of tubes extending inwardly an extent at least to the center of said frame so that the load engaging members may be moved to inward positions in contiguous relation with one another;

means for moving the load engaging members comprising -a separate crosshead for each load engaging member and a separate first piston and cylinder unit for each load engaging member connected at one end to its load engaging member and at its opposite end to its crosshead;

said means including a separate second piston and cylinder unit for each load engaging member connected at one end to the associated crosshead and at its opposite end to said frame in overlapping relation to the associated first piston and cylinder unit;

the cylinders of all said piston and cy inder units being disposed at all times Within the confines of said frame;

a horizontal guide rod secured to said frame;

a guide sleeve on said rod for each crosshead and secured to its crosshead;

each crosshead slidably engaging one of said guide tubes so that said crossheads are guided for horizontal movement;

and means whereby fluid under pressure may be supplied to said piston and cylinder units in a manner to contract or extend said load engaging members.

References Cited in the file of this patent UNITED STATES PATENTS 

